Elon Is Doing It Again: SpaceX Will Be The World’s Biggest AI Cloud

What it claims

SemiAnalysis argues that SpaceX can reach its revised target of about 13GW of AI datacenter capacity in 2027. The firm says it has already identified more than 9GW of capacity. That datacenter total exceeds the more than 8GW of power SemiAnalysis tracks under Elon Musk's companies, so power supply is often settled after construction starts. SemiAnalysis also forecasts that the TeraFab datacenter will be rented to third parties.

Evidence

The page gives build times by site:

• Colossus 1: the first retrofit took 122 days for 150MW.
• Colossus 2: took 91 days for 210MW.
• Project SPAM: a building in the middle of Colossus 2. Construction started October 5, 2026, with first tranches targeted for December 2026.
• MiniHard (Memphis): finished in about 5 months.
• "Gun Range" plot (Mississippi): expected to take about 4 months.

For comparison, SemiAnalysis puts typical greenfield builds at 8 to 12 months.

At Starbase, Texas, the site went from ground clearing in late August 2026 to vertical construction by late September. SemiAnalysis estimates it could exceed 1GW with Vera Rubin hardware. The site is deploying more than 1GW of APRs and has two gas pipelines under way. According to the Brownsville mayor, SpaceX is building fiber through the Port of Brownsville and looking at waterfront leases.

SemiAnalysis has "medium-high confidence" that TeraFab in Grimes County, Texas will include a datacenter. This rests on preconstruction work, local filings and an August 2026 clip of SpaceX representatives, who did not say the capacity would be for SpaceX use only.

On speed, the page cites labor of about 3,000 workers per GW. SemiAnalysis believes Tesla makes modular MEP equipment for these sites.

Power at Colossus 2

TVA has received service requests for Macrohard (700MW) and MiniHard (450MW). A 500kV gas-insulated substation next to MiniHard is due by December 31, 2026 and will connect to the Freeport substation.

The Southaven turbines can legally run 2.7GW nameplate today. A requirement signed July 30, 2026 cuts that to 1.24GW nameplate by July 2027. After the roughly 1.2GW grid connection, about 1.3GW of compute is left against 1.24GW of nameplate generation. Derating and non-IT load could leave a shortfall of up to about 300MW.

SemiAnalysis proposes several ways to close that gap:

• the nearly 6GWh BESS (5.9GWh being installed), with turbines cycling to charge it;
• SLA tiering between customer-facing and internal training clusters;
• a PUE of about 1.10 to 1.15;
• lower-power rack designs, with Project SPAM using half the fiber of others.

The firm also expects most temporary turbines at Colossus 2 to move to Starbase.

Limits

Most capacity figures are SemiAnalysis estimates from satellite imagery, filings and supply-chain checks, not SpaceX disclosures. The firm says the work at TeraFab could instead be support facilities such as onsite gas or a central utility plant. It also says permitting (JETI agreements, TCEQ pauses) may be slowing vertical construction there. The Colossus 2 power balance depends on SemiAnalysis's own IT MW assumptions. Details on the power solutions, an additional possible site, and pricing for SpaceX contracts are behind the paywall.